Various formulations of cyanamide have proven useful to agriculture as a fertilizer. A stable liquid formulation, hydrogen cyanamide (HyCyn), has shown efficacy as a spray to provide uniform bud break. When applied to soil, HyCyn is recognized for its short half-life and reduced dermal and oral toxicity. Alternatively, calcium cyanamide can be applied to soil and produce hydrogen cyanamide in situ. Cyanamide has also been investigated for use as a non-fuming soil treatment against soil pathogens, but results were seldom repeatable. Thus, there remains a need for a highly effective, long-acting, and non-fuming pre-plant biocide for weed, soil pathogen, and pest control. The present invention fulfills this and other needs.